1. Field of the Invention
The present invention relates to a voltage control apparatus for a camera having a high load construction such as a motor.
2. Description of the Prior Art
Motors have been build into or mounted on cameras for automatically feeding film through the camera. In these cameras, the heavy load which results when the motor feeds film lowers the power source's voltage. No problems exist when the power source is large enough to handle such a high load. However, when the capacity of the power source is small, as in the battery for a compact camera, the voltage drop under the heavy load causes erroneous operation of the electronic circuit that controls the camera's other functions.
In order to solve this problem, a voltage step-up arrangement such as a DC/DC converter can be provided to supply the camera's electronic circuitry with the necessary voltage. In one known system, the voltage step-up component is controlled always to operate with the power source from the time it is switched on. A problem exists with this system in that the consumption of the power source is large, due to the current consumption in the voltage step-up component and the motor, even when no high load is placed on the power source.
It has also been suggested to operate the voltage step-up component only when there is a high load from the motor. However, in a compact camera, the number of batteries used is small and therefore the capacity of the power source is also small. Additionally, it takes some time for the decreased voltage level due to the power source consumption to be restored after the release of the load. The battery voltage cannot be restored immediately up to the predetermined proper voltage when the operation of the voltage step-up component is stopped at the same time as the motor. Thus, erroneous operation of the electronic circuit for controlling the camera's efficiency is possible.